The first edition of this book established a niche as the only volume with a wide ranging review of analytical chemistry having a focus specific to environmental science. This new edition has been thoroughly revised to take full account of the rapid changes and development in the field over the past five years. Separation science, atomic spectroscopy and speciation determinations are areas in which significant developments have been made, and these are reflected in the new edition. The importance of the assessment of the effects of pollutants on real systems has been recognised by the restructuring of the chapter on biological testing and incorporation of a new one on environmental toxicology. Self-assessment questions have been added. Environmental science was one of the key concerns of the latter part of the twentieth century and will continue to be into the twenty-first. Concerns for environmental protection and public health worldwide have led to extensive legislation. The investigation and modelling of environmental systems, together with the implementation of laws and regulations, has led to a demand for a large number of environmental measurements, many of which are made by techniques falling within the broad range of analytical chemistry. Many professionals make regular use of data obtained by techniques of analytical chemistry. Thus, although not primarily analytical chemists or even chemists, they need sufficient knowledge of the background of analytical chemistry to judge the quality and limitations of the environmental data obtained. Very much the same situation arises in the academic world, where students are involved in environmental science studies or projects in which they need appropriate analytical chemistry information. Both analytical chemistry and environmental science have an extensive literature at varying levels of sophistication. However, there have been few attempts to link the two. This book sets out the background to analytical chemistry and covers the principles of its most important techniques. This is done in a way that enables a user to grasp the strengths and weaknesses of a technique, together with its principles of operation, without becoming enmeshed in the chemical small print. Links to environmental uses are indicated in broad terms and then exemplified in more detail by accounts of specific and important environmental problems.